1. Field of the Invention
The present invention concerns in general terms the control of polyphase rotary electrical machines, in particular the machines of this type that are reversible, such as alternator/starters.
The invention finds applications in particular in the field of motor vehicles. It applies more generally to any alternator or alternator/starter, motor/alternator or motor/alternator/starter, having a bridge of switches as voltage rectifying elements, driver circuits (“driver circuits” in English) to drive the switches, and at least one communication link between each driver circuit and a control circuit forming a regulator for the rectified voltage, and providing the control and management of starting.
2. Description of the Related Art
In a conventional alternator, which generally uses power diodes as voltage rectifying elements, the regulator (driven or not) usually includes a so-called self-starting function (“self-start” in English). This function is used to enable the alternator to output current, even if it has not received the instruction to do so (wire cut, connector broken or removed, etc), while the thermal engine of the motor vehicle is turning, causing the rotation of the alternator. This function may be based on the monitoring of a differential voltage between two phases of the alternator and the detection of a value above a predefined threshold. In the event of such detection, the regulator, which was in idle mode (in order to save on the energy drawn from the vehicle battery) is “woken up”, and the machine is started.
In the case of an alternator/starter, a motor/alternator or a motor/alternator/starter, but also an alternator using switches as voltage rectifying elements, it may be wished to use the same method. This method does however have the drawback of requiring two additional connections between the driver circuit and the control circuit. This is because, in order to have available two items of phase information at the control circuit, it is necessary to provide two additional connection terminals on the control or regulating module and also a phase output connection terminal at each power module including the switches.